1. Field of the Invention
This invention relates generally to safety shutters which act to block hazardous high-intensity light signals radiated from a connector terminating the transmission line conveying these signals when the connector is decoupled from an adapter for receiving these signals, thereby shielding the eyes of individuals exposed to this radiation.
More particularly, the invention resides in to a shutter module which fits onto a standard fiber-optics connector and is adapted to block radiation therefrom only when the connector is decoupled from the adaptor.
2. Status of Prior Art
Fiber-optics transmission systems are widely used to convey data, voice video and other modulated light signals of high intensity such as laser beam signals. The concern of the present invention is with the connector terminating a fiber-optics transmission line conveying high-intensity light signals to be received by an adapter coupled to the connector. The adapter which feeds the signals to a terminal unit centers the fibers to minimize insertion losses.
When it becomes necessary to repair or make changes in the system and to do so, one must decouple the adapter from the fiber-optics transmission line connector, it is usually not feasible to interrupt and switch off light signal transmission. As a consequence, the open front end of the connector is exposed to dirt, dust and other contaminants. And it also leaks into the atmosphere the high-intensity light rays.
To avoid contamination of the decoupled connector, it is known to cover it with a dust cover such as the cover disclosed in U.S. Pat. No. 6,299,398 (2002) to Lu. The Lu cover is attached to the connector when the connector is not in use and its front end is then exposed.
The more serious problem encountered with a decoupled fiber-optics connector is not contamination which is not a factor unless the connector is decoupled for a prolonged period, but the high-intensity light rays leaking from the front end of the connector the moment it is decoupled. Individuals in the proximity of the radiating connector run the risk of damage to their eyes, even to the point of blindness. This risk is comparable to that experienced when looking directly at the sun.
The prior art fully recognizes the safety hazards which arise when a xe2x80x9clivexe2x80x9d fiber-optics connector is decoupled so that it then radiates high-intensity light signals. And the prior art discloses various ways of coping with this unsafe condition. Thus U.S. Pat. No. 5,687,268 to Stephenson et al. discloses a safety shutter pivoted on a device associated with a fiber-optics connector which when swung down then blocks light rays radiating from the connector.
The 1998 U.S. Pat. No. 5,708,745 to Yamaji discloses laser beam rays radiated from a fiber-optics connector which are blocked by a pair of shield plates hinged to a casing surrounding the connector. These plates are swung out of the way when an adapter enters the doors to be coupled to the connector. Showing a similar arrangement is U.S. Pat. No. 6,206,577 (2001) to Hall et al. in which a pair of shutter doors prevents laser beams leakage from a fiber-optics connector.
Various other types of safety shutters for fiber-optics connectors are disclosed in the following U.S. patents:
1) U.S. Pat. No. 6,296,398 (2001) to Lu
2) U.S. Pat. No. 4,767,179 (1988) to Sampson et al.
3) U.S. Pat. No. 6,302,592 (2001) to Zullig
In view of the foregoing, the main object of this invention is to provide a self-sufficient, safety shutter module adapted to fit onto a fiber-optics connector to block radiation emanating from the connector of high-intensity light signals only when the connector is decoupled from an adapter or other device for receiving these signals.
More particularly, an object of this invention is to provide a cap-like module that fits onto a standard connector terminating a xe2x80x9clivexe2x80x9d fiber-optics transmission line, the attachment of the module to the connector requiring no screws of similar fasteners.
Among the significant advantages of a module in accordance with the invention are the following:
A. The module is a unitary structure in which all components of the module are integrated.
B. The module can be tailored to conform to any existing type of fiber-optics connector and therefore does not require a specially-made connector.
C. The module requires no maintenance and can be mass-produced at relatively low cost.
Briefly stated, these objects are attained in a safety shutter module adapted to fit onto a standard fiber-optics connector which terminates a transmission line conveying light signals of high intensity to be received by an adapter when it is coupled to the connector. When decoupled, these light signals leak from the open front end of the connector and are radiated therefrom. This radiation is hazardous to the eyes of individuals exposed thereto.
The module is composed of a cap that fits onto the connector and is provided with a visor that projects beyond the front end, the visor having a hinged shutter plate that depends therefrom to block the radiation. But when the adapter is plugged into the connector, it acts to swing the shutter plate upwardly against the visor to admit the adapter and unblock the connector.